U.S. patent number 11,056,413 [Application Number 16/417,845] was granted by the patent office on 2021-07-06 for combined inductor and heat transfer device.
This patent grant is currently assigned to International Business Machines Corporation. The grantee listed for this patent is International Business Machines Corporation. Invention is credited to Todd Takken, Shurong Tian, Yuan Yao, Xin Zhang.
United States Patent |
11,056,413 |
Zhang , et al. |
July 6, 2021 |
Combined inductor and heat transfer device
Abstract
An inductor includes a conductor having a first end and a second
end, wherein the first end, the second end, or both ends are
configured to be mounted on a substrate and configured to receive a
heat flow; and one or more magnetic cores surrounding a first
portion of the conductor, the first portion of the conductor being
intermediate the first end and the second end of the conductor. A
second portion of the conductor not surrounded by the one or more
magnetic cores is configured to transfer the heat flow from the
conductor.
Inventors: |
Zhang; Xin (Yorktown Heights,
NY), Takken; Todd (Brewster, NY), Tian; Shurong
(Mount Kisco, NY), Yao; Yuan (Tarrytown, NY) |
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
1000005661887 |
Appl.
No.: |
16/417,845 |
Filed: |
May 21, 2019 |
Prior Publication Data
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|
Document
Identifier |
Publication Date |
|
US 20200373217 A1 |
Nov 26, 2020 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
23/645 (20130101); H01L 28/10 (20130101); H01L
23/367 (20130101) |
Current International
Class: |
H01L
49/02 (20060101); H01L 23/64 (20060101); H01L
23/367 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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108990362 |
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Dec 2018 |
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CN |
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2 797 090 |
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Oct 2014 |
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EP |
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1 756 935 |
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Sep 2016 |
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EP |
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2010149673 |
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Dec 2010 |
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WO |
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Primary Examiner: Bradley; Stephen M
Assistant Examiner: Ramallo; Gustavo G
Attorney, Agent or Firm: Harrington & Smith
Government Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government support under Contract No.:
B621073 awarded by Department of Energy. The Government has certain
rights in this invention.
Claims
What is claimed is:
1. An inductor, comprising: a conductor having a first end and a
second end, wherein the first end, the second end, or both ends are
configured to be mounted on a substrate and configured to receive a
heat flow; one or more magnetic cores surrounding a length of,
forming a closed loop around, and being in continuous contact with
a first portion of the conductor, the first portion of the
conductor being intermediate the first end and the second end of
the conductor; wherein a second portion of the conductor not
surrounded by the one or more magnetic cores is configured to
transfer the heat flow from the conductor.
2. The inductor of claim 1, wherein one or more magnetic cores
comprises a recessed portion configured to accommodate the
conductor therein, when two or more magnetic cores are coupled
together around the conductor.
3. The inductor of claim 2, wherein the two or more magnetic cores
are configured to be coupled around the conductor to form one or
more gaps between the magnetic cores.
4. The inductor of claim 1, further comprising a heat sink disposed
on the second portion of the conductor not surrounded by the one or
more magnetic cores to transfer the heat flow from the
conductor.
5. The inductor of claim 4, wherein the heat sink comprises a
planar base coupled to the second portion of the conductor and at
least one fin extending substantially perpendicularly from the
planar base.
6. The inductor of claim 4, further comprising a thermal interface
material between the heat sink and the conductor.
7. The inductor of claim 4, wherein the heat sink is integrated
with the second portion of the conductor.
8. The inductor of claim 1, further comprising a cold plate
disposed on the second portion of the conductor not surrounded by
the one or more magnetic cores to transfer the heat flow from the
conductor.
9. The inductor of claim 8, wherein the cold plate comprises a
container having an inlet and an outlet through which a fluid may
flow.
10. The inductor of claim 8, further comprising a thermal interface
material between the cold plate and the conductor.
11. The inductor of claim 8, wherein the cold plate is integrated
with the second portion of the conductor.
12. An inductor, comprising: a conductive winding, the conductive
winding comprising an elongated member having a first end and a
second end through which electrical current can flow; one or more
magnetic cores surrounding a length of, forming a closed loop
around, and being in continuous contact with a portion of the
conductive winding; wherein a portion of the conductive winding not
enclosed by the one or more magnetic cores is configured to conduct
heat away from the conductive winding.
13. The inductor of claim 12, further comprising conductive pads on
the first end of the elongated member and the second end of the
elongated member, one or both of the conductive pads being
configured to receive heat from an electrical component.
14. The inductor of claim 12, further comprising a heat mitigating
element disposed on the portion of the conductive winding not
enclosed by the one or more magnetic cores.
15. The inductor of claim 14, wherein the heat mitigating element
is a heat sink.
16. The inductor of claim 14, wherein the heat mitigating element
is a cold plate.
17. The inductor of claim 14, further comprising a thermal
interface material between the heat mitigating element and the
conductive winding.
18. A method, comprising: providing a conductor through a magnetic
core, the conductor having a first end and a second end, the first
end and the second end configured to be mounted on a substrate, and
the magnetic core surrounding a length of, forming a closed loop
around, and being in continuous contact with a first portion of the
conductor, the first portion of the conductor being intermediate
the first end and the second end of the conductor; conducting
current through the conductor with an inductance created by a
current loop and the magnetic core; conducting heat to the
conductor; and transferring the heat away from the conductor.
19. The method of claim 18, wherein transferring the heat away from
the conductor comprises transferring the heat to a heat sink.
20. The method of claim 18, wherein transferring the heat away from
the conductor comprises transferring the heat to a cold plate.
Description
BACKGROUND
The exemplary embodiments described herein relate generally to
semiconductor structures and, more specifically, to the use of
inductors to improve heat dissipation in semiconductor devices.
Various electrical components, such as semiconductor devices, on a
circuit board generate heat. It is desirable to remove heat in
order to maintain the temperatures of the components within their
respective functional operating ranges. Conventional methods of
cooling generally remove heat from the components directly through
heat conducting elements such as heat sinks or heat spreaders that
are kept in contact with the components. However, it is often
difficult to obtain direct contact with smaller components on the
circuit board. Air cooling techniques may be used in some
circumstances, but such techniques may have limited efficacy with
regard to cooling components having shorter profiles. Thus, both
heat sinks and air cooling techniques may be limited in their
abilities to effectively remove heat from the components as well as
from the surface of the circuit board itself.
BRIEF SUMMARY
In accordance with one aspect, an inductor comprises a conductor
having a first end and a second end, wherein the first end, the
second end, or both ends are configured to be mounted on a
substrate and configured to receive a heat flow; and one or more
magnetic cores surrounding a first portion of the conductor, the
first portion of the conductor being intermediate the first end and
the second end of the conductor. A second portion of the conductor
not surrounded by the one or more magnetic cores is configured to
transfer the heat flow from the conductor.
In accordance with another aspect, an inductor comprises a
conductive winding, the conductive winding comprising an elongated
member having a first end and a second end through which electrical
current can flow; and one or more magnetic cores enclosing a
portion of the conductive winding. A portion of the conductive
winding not enclosed by the one or more magnetic cores is
configured to conduct heat away from the conductive winding.
In accordance with another aspect, a method comprises providing a
conductor through a magnetic core, the conductor having a first end
and a second end, the first end and the second end configured to be
mounted on a substrate, and the magnetic core surrounding a first
portion of the conductor, the first portion of the conductor being
intermediate the first end and the second end of the conductor;
conducting current through the conductor with an inductance created
by a current loop and the magnetic core; conducting heat to the
conductor; and transferring the heat away from the conductor.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing and other aspects of exemplary embodiments are made
more evident in the following Detailed Description, when read in
conjunction with the attached Drawing Figures, wherein:
FIG. 1A is an exploded perspective view of an inductor having four
magnetic cores;
FIG. 1B is a perspective view of the inductor of FIG. 1A showing
the magnetic cores closed around a conductor;
FIG. 1C is a perspective view of the inductor of FIG. 1A in which
the magnetic cores, when coupled to the conductor, include
longitudinal gaps;
FIG. 2A is an exploded perspective view of an inductor having four
magnetic cores and a heat sink;
FIG. 2B is a perspective view of the inductor of FIG. 2A showing
the magnetic cores closed around the conductor and the heat sink
positioned on the conductor;
FIG. 2C is a perspective view of the inductor of FIG. 2A in which
the magnetic cores, when coupled to the conductor, include
longitudinal gaps;
FIG. 3A is an exploded perspective view of an inductor having four
magnetic cores and a cold plate;
FIG. 3B is a perspective view of the inductor of FIG. 3A showing
the magnetic cores closed around the conductor and the cold plate
positioned on the conductor;
FIG. 3C is a perspective view of the inductor of FIG. 3A in which
the magnetic cores, when coupled to the conductor, include
longitudinal gaps;
FIG. 4A is a perspective view of a circuit board on which the
inductor of FIG. 1B is mounted; and
FIG. 4B is a perspective view of a circuit board on which two
inductors are mounted.
DETAILED DESCRIPTION
The word "exemplary" is used herein to mean "serving as an example,
instance, or illustration." Any embodiment described herein as
"exemplary" is not necessarily to be construed as preferred or
advantageous over other embodiments. All of the embodiments
described in this Detailed Description are exemplary embodiments
provided to enable persons skilled in the art to make or use the
invention and not to limit the scope of the invention which is
defined by the claims.
Referring to FIGS. 1A-1C, one exemplary embodiment of an inductor
structure having improved thermal conductivity suitable for use as
a path for transferring heat from semiconductors devices or other
circuit board components is shown generally at 100 and is
hereinafter referred to as "inductor 100." Inductor 100 comprises a
conductor 110 around which one or more magnetic cores 120 are
mounted, with four magnetic cores 120 being shown in the Figures.
The conductor 110 operates as a winding for the inductor 100. At
least two magnetic cores 120 are disposed around the conductor 110
to provide a path for magnetic flux. Each magnetic core 120 is
generally a ferrite material having high magnetic permeability and
low electrical conductivity. Ferrite materials that may be used to
form the magnetic core 120 are generally iron oxides combined with
manganese, zinc, and/or nickel, although other materials may be
used. In embodiments in which two or more magnetic cores 120 are
used, the magnetic cores may include different materials.
Additionally, in embodiments in which two or more magnetic cores
120 are used, the magnetic cores may be of different sizes.
As shown in FIG. 1A, each of the magnetic cores 120 may include a
recess 126 or other type of recessed portion that extends from one
end to an opposing end such that when two magnetic cores 120 are
coupled together, non-magnetic openings are formed at opposing ends
of the assembled magnetic cores 120. As shown in FIG. 1B, each
recess 126 is configured to accommodate the conductor 110 when the
magnetic cores 120 are closed around the conductor 110. As shown in
FIG. 1C, each of the magnetic cores 120 may be coupled around the
conductor 110 so as to form gaps 130 extending lengthwise along the
magnetic cores 120. The gaps 130 may help to mitigate magnetic flux
saturation in the inductor 100. In addition, because the width of
each of gap 130 is very small, the magnetic field leakage of the
gaps is negligible. As shown in FIG. 1B, the width of each gap 130
may be reduced to zero to form a completely closed magnetic loop
thereby maximizing inductance and the Q value of the inductor 100.
In some embodiments, only one of the two magnetic cores 120
assembled around the conductor 110 may include the recess 126.
The conductor 110 may be formed from one metal piece, for example,
by a stamping operation. As shown, the end portions of the
conductor 110 are bent so as to define two feet 150 located at a
bottom (board) side such that the conductor extends from a first of
the two feet 150 through a first of the magnetic cores 120, through
a turn in a substantially perpendicular direction to extend along
an upper length 160, through a second turn to extend in another
substantially perpendicular direction and substantially parallel to
the extension of the conductor 110 through a first assembly of the
magnetic cores 120 and through a second assembly of the magnetic
cores 120, and to the second of the two feet 150. The upper length
160 provides a substantially planar surface. The material of the
conductor 110 extends beyond the magnetic core region such that
inner surfaces of the magnetic cores 120 allow thermal contact to
be made with the conductor 110. When assembled with magnetic cores
120, the feet 150 are mounted to a circuit board or other substrate
(for example, by soldering to conductive pads 152 or the like). A
connection of the feet 150 to the circuit board may provide a path
through which the inductor 100 is driven or otherwise powered, for
example, by the flow of electric current.
Referring to FIGS. 2A-2C, another exemplary embodiment of an
inductor structure having improved thermal conductivity is shown
generally at 200 and is hereinafter referred to as "inductor 200."
Inductor 200 is similar to inductor 100 and includes a conductor
210 and magnetic core(s) 220, but inductor 200 includes a cooling
element in the form of a heat sink 280 for dispersing heat from (1)
the conductor 210, (2) semiconductors devices or other circuit
board components proximate the inductor 200, and/or (3) a circuit
board or other substrate onto which the inductor 200 is mounted
(e.g., by soldering or the like). The conductor 210 may have feet
250 that are mounted on pads 252.
As shown in FIG. 2A, the heat sink 280 comprises a base 282, which
may be a substantially planar element, having a plurality of fins
284 extending substantially perpendicularly from an upper surface
of the base 282, with a lower surface of the base 282 being in
contact with the conductor 210 through a thermal interface material
286. In some exemplary embodiments, the heat sink 280 may be
fabricated of metal, such as aluminum, copper, or any other
suitable metal or alloy and may be coupled to the conductor 210
through the thermal interface material 286 or formed as an
integrated unit with the conductor 210. The thermal interface
material 286 may comprise any suitable material capable of
facilitating effective thermal contact between the heat sink 280
and the conductor 210. In some exemplary embodiments, the thermal
interface material 286 may comprise an adhesive or tape.
As shown in FIG. 2B, the heat sink 280 is mounted on a portion of
the conductor 210 exposed outside the magnetic region. As shown,
the portion of the conductor 210 exposed outside the magnetic
region is intermediate the magnetic cores 220. As shown in FIG. 2C,
two magnetic cores 220 may be coupled around the conductor 210 so
as to form gaps 230 extending lengthwise along the magnetic cores
220. The gaps 230 may help to mitigate magnetic flux saturation in
the inductor 200.
Referring to FIGS. 3A-3C, another exemplary embodiment of an
inductor structure having improved thermal conductivity is shown
generally at 300 and is hereinafter referred to as "inductor 300."
Inductor 300 is similar to inductor 100 and includes a conductor
310 and magnetic core(s) 320, but inductor 300 includes a cooling
element in the form of a cold plate 380 for dispersing heat from
(1) the conductor 310, (2) semiconductors devices or other circuit
board components proximate the inductor 300, and/or (3) a circuit
board onto which the inductor 300 is mounted (e.g., by soldering or
the like). The conductor 310 may have feet 350 that are mounted on
pads 352.
As shown in FIG. 3A, the cold plate 380 is a container having an
inlet 382 and an outlet 384 through which a fluid (a gas or a
liquid, such as water) may be caused to flow. A surface of the cold
plate 380 may be disposed on the conductor 310 through a thermal
interface material 386. As with the inductor 200, the thermal
interface material 386 may comprise any suitable material (as
indicated above) capable of facilitating effective thermal contact
between the cold plate 380 and the conductor 310. In some
embodiments, however, the cold plate 380 may be an integrated unit
with the conductor 310.
As shown in FIG. 3B, the cold plate 380 is mounted on a portion of
the conductor 310 exposed outside the magnetic region. As shown,
the portion of the conductor 310 exposed outside the magnetic
region is intermediate the magnetic cores 320. As shown in FIG. 3C,
two magnetic cores 320 may be coupled around the conductor 320 so
as to form gaps 330 extending lengthwise along the magnetic cores
320. The gaps 330 may help to mitigate magnetic flux saturation in
the inductor 300.
Referring to FIG. 4A, one exemplary embodiment of a circuit board
on which the inductor 100 may be mounted is shown generally at 400.
As shown, one or more inductors 100 may be mounted on a surface of
the circuit board 400 proximate electrical components 410 (or any
semiconductor device). The feet 150 of the inductors 100 may be
mounted on the conductive pads 152 on the surface of the circuit
board 400 using any suitable means (e.g., soldering or the like).
Heat generated from the electrical components 410 is generally
transferred to the conductors 110 and to the upper lengths 160
where it is dissipated to the atmosphere. Although the inductors
100 are shown without heat sinks 280 or cold plates 380, such
elements may be incorporated into the inductors (such that the
circuit board 400 may employ inductors 200 or inductors 300).
Referring to FIG. 4B, two or more inductors 100 (or inductors 200,
300) may be mounted to the circuit board 400.
The inductors 100, 200, 300 as proposed herein may address problems
associated with the cooling of circuit board components having
shorter profiles. In particular, air cooling such components using
techniques of the prior art may have limited efficacy. The
inductors 100, 200, 300 as proposed herein overcome the problems of
the prior art techniques by providing improved thermal conductivity
over an overall height of an inductor 100, 200, 300, e.g., from the
feet 150 to the upper length 160 (as in inductor 100), which
permits improved contact to a heat sink 280 or cold plate 380 (in
exemplary embodiments in which the heat sink 280 or cold plate 380
is employed). The heat generated from the inductor 100 itself, from
the electrical components around the inductor 100, and from the
circuit board 400 onto which the inductor 100 is mounted will be
removed more effectively.
In one example, an inductor comprises a conductor having a first
end and a second end, wherein the first end, the second end, or
both ends are configured to be mounted on a substrate and
configured to receive a heat flow; and one or more magnetic cores
surrounding a first portion of the conductor, the first portion of
the conductor being intermediate the first end and the second end
of the conductor. A second portion of the conductor not surrounded
by the one or more magnetic cores is configured to transfer the
heat flow from the conductor.
One or more of the magnetic cores may comprise a recessed portion
configured to accommodate the conductor therein, when two or more
magnetic cores are coupled together around the conductor. The two
or more magnetic cores may be configured to be coupled around the
conductor to form one or more gaps between the magnetic cores. The
inductor may further comprise a heat sink disposed on the second
portion of the conductor not surrounded by the one or more magnetic
cores to transfer the heat flow from the conductor. The heat sink
may comprise a planar base coupled to the second portion of the
conductor and at least one fin extending substantially
perpendicularly from the planar base. The inductor may further
comprise a thermal interface material between the heat sink and the
conductor. The heat sink may be integrated with the second portion
of the conductor. The inductor may further comprise a cold plate
disposed on the second portion of the conductor not surrounded by
the one or more magnetic cores to transfer the heat flow from the
conductor. The cold plate may comprise a container having an inlet
and an outlet through which a fluid may flow. The inductor may
further comprise a thermal interface material between the cold
plate and the conductor. The cold plate may be integrated with the
second portion of the conductor.
In another example, an inductor comprises a conductive winding, the
conductive winding comprising an elongated member having a first
end and a second end through which electrical current can flow; and
one or more magnetic cores enclosing a portion of the conductive
winding. A portion of the conductive winding not enclosed by the
one or more magnetic cores is configured to conduct heat away from
the conductive winding.
The inductor may further comprise conductive pads on the first end
of the elongated member and the second end of the elongated member,
one or both of the conductive pads being configured to receive heat
from an electrical component. The inductor may further comprise a
heat mitigating element disposed on the portion of the conductive
winding not enclosed by the one or more magnetic cores. The heat
mitigating element may be a heat sink or a cold plate. The inductor
may further comprise a thermal interface material between the heat
mitigating element and the conductive winding.
In another example, a method comprises providing a conductor
through a magnetic core, the conductor having a first end and a
second end, the first end and the second end configured to be
mounted on a substrate, and the magnetic core surrounding a first
portion of the conductor, the first portion of the conductor being
intermediate the first end and the second end of the conductor;
conducting current through the conductor with an inductance created
by a current loop and the magnetic core; conducting heat to the
conductor; and transferring the heat away from the conductor.
Transferring the heat away from the conductor may comprise
transferring the heat to a heat sink. Transferring the heat away
from the conductor may comprise transferring the heat to a cold
plate.
In the foregoing description, numerous specific details are set
forth, such as particular structures, components, materials,
dimensions, process or method steps, and techniques, in order to
provide a thorough understanding of the exemplary embodiments
disclosed herein. However, it will be appreciated by one of
ordinary skill of the art that the exemplary embodiments disclosed
herein may be practiced without these specific details.
Additionally, details of well-known structures or process or method
steps may have been omitted or may have not been described in order
to avoid obscuring the presented embodiments.
The description of the present invention has been presented for
purposes of illustration and description, but is not intended to be
exhaustive or limiting in the form disclosed. Many modifications
and variations will be apparent to those of ordinary skill in the
art without departing from the scope of the invention. The
embodiments were chosen and described in order to best explain the
principles of the invention and the practical applications, and to
enable others of ordinary skill in the art to understand the
invention for various embodiments with various modifications as are
suited to the particular uses contemplated.
* * * * *